The present invention relates generally to agricultural planter units, and more particularly relates to row marker lift controls having automatic sequencing mechanisms which alternately cause each row marker to be lifted and lowered.
Automatic row marker lift mechanisms are well known in the art. Those mechanisms employ mechanical as well as electric and hydraulic means to raise and lower the row marker. These mechanisms are mounted on the implements structure or toolbar and include lever members, cable means and other bulky exposed elements that limit the ability to mount tools or other necessary parts on the implement. The mechanisms are exposed to weather, foreign matter and provide moving elements posing safety hazzards. Many mechanisms provide duplicate systems including separate hydraulic lift cylinders that increase cost and maintenance and reduce usable toolbar space.
Actuation of the row marker movement has been tied to tractor movement, planter or grain drill earth engagement, electrical signals, and the hydraulic system.